CF-1 Flow Calibrator for Dilution Probe Verification

Taking an odor sample from an emission stream is often not straightforward. The temperature and humidity can lead to condensation in the sampling bag, which is highly undesirable. Ultimately, we aim for a representative gas sample. The solution is to dilute the sample with odorless air. In practice, dry nitrogen is often used to bring the humidity below the dew point and prevent reactions with gases from the emission stream. The dilution probes used for this purpose utilize a critical capillary and a venturi. This ensures the sampling flow and the dilution ratio are known.

Accurate Dilution with CF-1

Measurement standards require proof of proper functioning of the dilution probe and knowledge of the exact dilution ratio. With the CF-1 Flow Calibrator, exact flows can be easily and quickly determined in the field! The core of this flow calibrator is a laminar flow element. In a laminar flow element, the medium passes through a bundle of tubes. The flow becomes laminar, and due to the resistance of this bundle, a pressure drop can be measured. This pressure drop is directly proportional to the flow rate.

The dynamic range of the CF-1 is 1:100. For applications involving dilution probe verification, the model with a range of 50–5000 ml/min is most suitable (CF-1 LF). The unit can be connected to either the pressure or suction side. This makes it very easy to measure both the sampling flow and the total flow inside the dilution probe.

Source: Infomil Practice Sheet L40-13P

Specifications CF-1 LF:

The final determination of the actual odor concentration is carried out by an odor panel. With an olfactometer, stepwise dilutions of an air sample are presented in comparison to reference air. The result is an odor concentration in European Odor Units per cubic meter [ouE]. Therefore, a pre-dilution often takes place during emission measurements.